Volvo MD2040 Gearbox Fail

[Kennavin]

Our Volvo MD2040 gearbox has failed and we are desperately looking for a new one.

Should we fail to find one, I assume we would have to look at a total engine replacement.

I would welcome thoughts and advice, or if anyone has had a similar quandary?

Many thanks in advance

[belizesailor]

Im not following the reasoning behind going from a gearbox repair/replace to a full repower?

To my knowledge these gear boxes and parts for them are still avaible. They show up as avaible on MarinePartsExpress so why not just repair it? Marine diesel gear boxes are relatively simple.

What kind of failure did it have?

[Emmalina]

What exactly does fail mean ? Obviously something has broken but be a bit more specific ! I had a VP gearbox "fail" when the spline on the shaft rusted/striped. I was told new gearbox but took it to a machine shop and got it converted to hex drive and made a plate for the flywheel !. Better than original in the end.

[Kennavin]

The bung had popped out of gearbox and the oil was in the bilge. No idea how long it had been like that and it is now seized

[Kennavin]

BelizeSailor,

Im struggling to find a 3:1 replacement MS2AD in the UK - a few 2:1 on eBay which will impact performance and require a new prop.

Do you know if I can just use a MS2AE as a direct replacement? Or will I need to customise my MD2040?

Appreciate your guidance...

Many thanks in advance!

[Emmalina]

If its just the bearings seized then it should be recoverable .

[belizesailor]

Originally Posted by Kennavin

BelizeSailor,

Im struggling to find a 3:1 replacement MS2AD in the UK - a few 2:1 on eBay which will impact performance and require a new prop.

Do you know if I can just use a MS2AE as a direct replacement? Or will I need to customise my MD2040?

Appreciate your guidance...

Many thanks in advance!

I dont know for sure on the compatiblity, but have you cracked it open yet to see what actually failed?

[billgewater]

1) The gearbox has to be removed or worse, the complete engine. I know which one I would rather be doing.
2) It sounds to me that the gearbox is able to be repaired. Seizure is normally restricted to bearing damage, so is usually simple to fix.
3) to replace the entire engine/gearbox entails not only much time, but much effort, and much money. Usually, half the other stuff in the engine space needs re jigging or replacement.

Make contact with a marine transmission company. They will give you good advice; particularly how to remove the gearbox i.e. the correct sequence and how to manage the weight of the box in the engine room. It is standard stuff for these companies and they can usually quote for removal, repair and re-installation.

When you say the oil bung "popped" out just what could have possibly caused this? These bungs usually have soft copper washers tapered threads etc. A "popped" bung sounds a bit weird to me. If the gearbox is hydraulic then often the internal pressure is often around 130 psi i.e. leaks will show up quickly. So how long after the last oil change did this problem arise?
If the box is hydraulic, then maybe adding a gauge to the oil cooling line could be useful.
If the gearbox is overhauled, it should come back with new clutch plates, seals etc. Damper plates can be checked etc. The gearbox is not the item you want to fail when things get adventurous such as motoring off a lee shore or entering a marina berth.

[belizesailor]

Originally Posted by Kennavin

The bung had popped out of gearbox and the oil was in the bilge. No idea how long it had been like that and it is now seized

I bet its just a bearing.

And pulling the gear box off a MD2040 is not hard. You will want a helper though.

Is there a shop near you who could just pull it and evaluate it for you?

Be a shame to waste serious $s on a new gearbox/engine instead of just making a simple bearing replacement.

[Emmalina]

Originally Posted by billgewater

1) The gearbox has to be removed or worse, the complete engine. I know which one I would rather be doing.
2) It sounds to me that the gearbox is able to be repaired. Seizure is normally restricted to bearing damage, so is usually simple to fix.
3) to replace the entire engine/gearbox entails not only much time, but much effort, and much money. Usually, half the other stuff in the engine space needs re jigging or replacement.

Make contact with a marine transmission company. They will give you good advice; particularly how to remove the gearbox i.e. the correct sequence and how to manage the weight of the box in the engine room. It is standard stuff for these companies and they can usually quote for removal, repair and re-installation.

When you say the oil bung "popped" out just what could have possibly caused this? These bungs usually have soft copper washers tapered threads etc. A "popped" bung sounds a bit weird to me. If the gearbox is hydraulic then often the internal pressure is often around 130 psi i.e. leaks will show up quickly. So how long after the last oil change did this problem arise?
If the box is hydraulic, then maybe adding a gauge to the oil cooling line could be useful.
If the gearbox is overhauled, it should come back with new clutch plates, seals etc. Damper plates can be checked etc. The gearbox is not the item you want to fail when things get adventurous such as motoring off a lee shore or entering a marina berth.

Its not hydraulic !

[Kennavin]

The boat is new to us. There was a pool of oil under the engine in the bilge and as we were cleaning it out we found the bung in the dirty oil. My thought is that the previous owner, or previous service did not put the bung back in with the copper washer...

And this is how it started

[Kennavin]

So I had someone look at the gearbox and the cones are damaged. The gearbox was a MS2AD ratio 3:1.

All of the secondhand MS2ADs that Ive found are 2:1 which means a prop replacement.

I did find out that there is very little difference between the MS2AD and MS2AE. The "E" was the follow-on model to the D. The difference was that the E model had shot peened gear wheels for a bit more strength, and the E used heavy gear oil instead of engine oil. It will be a direct fit as it same bolt holes etc

I managed to find a MS2AE with a 3:1 ration on eBay for £450 so I will be replacing my old gearbox this weekend. And I will be ensuring the bung has a copper washer!!

Thank you all for your help and messages! Very kind!

I hope you all have a lovely weekend...